Friction conveyor



United States Patent Lucas Jones Conrad Winston-Salem;

Gerard Eugene Leonard, Kernersville; Colin Shaw McArthur; John Raymond Everhart, Winston-Salem, N.C.

21] Appl. No. 761,029

[72] inventors [22] Filed Sept. 20, 1968 [45] Patented Dec. 15, 1970 [73] Assignee R. J. Reynolds Tobacco Company Winston-Salem, N.C. a corporation of New Jersey [54] FRICTION CONVEYOR l 1 Claims, 9 Drawing Figs.

[52] U.S.Cl 209/116; 2|4/2l8 [5]] Int. Cl B65g 25/00; B07b l3/l0 [50] Field ofSear-ch l98/2l8,

220-D-20; 209/l I5, 116, 117

[56] References Cited UNITED STATES PATENTS 2,337,174 l2/l943 Bebinger ..l98/220(-D-20) FOREIGN PATENTS 553,l ll 6/l957 Belgium 209/116 Primary Examiner-Hugo O. Schulz AIl0meys-Robert S. Dunham, P. E, Henninger, Lester W. Clark, Gerald W. Griffin, Thomas F. Moran, Howard J. Churchill, R. Bradlee Boal, Christopher C. Dunham and Thomas P. D owd ABSTRACT: An oscillating conveyor apparatus executing slow forward motion, quick reverse and rapid return comprising a member to which a conveyor pan is attached, which member is constrained to move between two spaced springs having different spring rates. The spring with the higher spring rate causes the member upon impact to rapidly reverse its motion, while the spring of lower spring rate more slowly reverses the motion of the oscillating member. The springs thus produce a motion having a slow forward stroke, quick reversal at the end of the forward stroke, a return stroke faster than the forward stroke, and a reversal at the end of the return stroke relatively slow as compared to that at the end of the forward stroke. A pneumatic motor is provided to communicate an additional force to the member, preferably during its rapid return motion, to overcome frictional losses in the apparatus and maintain continuous oscillation of the member between the two springs. The operation of the motor is controlled by suitable valves which operate in response to the motion of the piston. The resulting motion of the conveyor pan causes articles or material resting thereon to move forward along the surface of the pan.

PATENTED DEC] 5 I978 SHEET 2 BF 4 PATENTEDnm 5 19m SHEET Q BF 4 QEQQNQQ \m T/ME T/ME

Fig. 5

Fig.

FRICTION CONVEYOR BACKGROUND OF THE INVENTION The present invention relates to the conveyor art and more particularly to a conveyor device of the friction or shuffle type.

Shuffle conveyors are generally known for moving commodities having a large number of particulate elements such as coal, flour, sand and the like as well as some items of manufacture such as paper clips.

These conveyors work on a principle of oscillating or reciprocal motion wherein the forward motion of the conveying surface is abruptly reversed and, by virtue of the inertia of the items being conveyed, the sliding friction between the items and the surface of the conveying means is overcome so that the items are caused to move or slide forward on the conveying surface.

A particular problem arises in connection with this type of conveyor when the elements being conveyed are of varying coefficients of friction. For the particles with a large coefficient of friction, a significant impact or abrupt reversal is required so that their inertia will be sufficient to cause them to overcome the frictional resistance tosliding, and travel forward relative to the pan surface. This occurs during the large deceleration and acceleration of the pan occurring at impact. The elements with low coefficients of friction, on the other hand, are essentially sliding at all times when the conveyor surface is in motion. Thus, it is necessary to impart a forwardly accelerating force to these elements for a greater period of time than is given for the return motion of the conveyor surface during its oscillations. With this differential motion, the low coefficient of friction particles will achieve relative forward motion on the conveyor surface, and should the particles stick to the surface during the forward stroke, they will still move forward if they slide during at' least part of the return stroke. It is thus necessary to combine the respective impact and differential motions in the oscillations of the conveyor surface to insure that all of the conveyed particles will move forward with respect to the surface.

SUMMARY OF THE lNVENTlON The present invention embodies anapparatus which produces the necessary combination of impact and differential motion in a conveyor pan transporting items of different coefticients of friction, such as processed foods, and particularly, separated chicken parts. The particular embodiment described herein utilizes a spring system having differing spring rates, which produces the continuous oscillating motion in the manner required, in combination with a simple pneumatic motor which contributes an additional force during the return stroke, just sufficient to overcome frictional losses in the apparatus, so that a minimum power input is required. Two springs interact in the system to produce motion having a slow forward stroke, quick reversal at the end of the forward stroke, a return stroke faster than the forward stroke, and a reversal at the end of the return stroke relatively slow as compared to that at the end of the forward stroke.

It is-therefore an object of the pres'ent'invention to provide an improved conveyor of the friction or shuffle type, which will transport items of both large and low coefficients of friction by combining both impact and differential motion in a manner which insures the advancement of all particulate elements transported thereon. It is a more'particular object of the present invention to provide an improved spring system for producing impact and differential motion in a desired pattern with a minimum of power input to drive conveying means which will advance separated chicken parts between two stations in a processing line. Other and further objects and advantages of the invention will become apparent to those skilled in the art, from a consideration of the following description and claims, taken together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an apparatus for separating chicken parts including the improved friction conveyor of the present invention;

FIG. 2 is a fragmentary longitudinal sectional view of the apparatus shown in FIG. 1; 7

FIG. 3 is an end view of the friction conveyor of the present invention taken along the lines 3-3 of FIG. 2; Y

FIG. 4 is a plan view of the improved drive means for the friction conveyor of the present invention; 1

FIG. 5 is a side view of the improved drive means taken i along the lines 5-5 of FIG. 4;

FIG. 6 is a perspective view of a modified form of the DETAILED DESCRIPTION The improved friction conveyor of the present invention will be particularly described in connection with apparatus for separating chicken parts which include pieces of both high and low coefficients of friction but it will be understood that it may have application in any type of system using shuffle'conveyors.

FIG. 1 shows a preferred apparatus incorporating the improved friction conveyor wherein the' chicken meat is separated from the bones and then sorted and passed for further processing. The apparatus comprises a movable platform I on which an operator stands and introduces the whole chicken parts, e.g., wings or legs into a disuniter device 2. The improved conveyor 3 is mounted on a frame member 4 and extends into a rotatable drum 5. The conveyor drive means is located within the housing 6 which is attached to an extension 4a fixed to the support frame 4. Both the drumS and conveyor 3-are tiltably mounted and are inclined downwardly in the direction of movement of the chicken parts.

The drum 5 and frame 4 are disclosed in greater detail in the copending application of Conrad and Everhart, Ser. No. 761,179 filed Sept. 20, 1968 Now Pat. No. 3,508,646 and as signed to the assignee of the present application. The disuniter device 2 may be of a type such as disclosed in the copending application of Conrad and Alldred, Ser. No. 759,709 filed Sept. 13, 1968 and assigned to the assignee of the present application. I

As best understood with reference to FIG. 2, the chicken parts when passing through the disuniter 2 are acted upon to separate the meat portions from the bones. The mixed meat and bones drop from the disuniter 2 onto the interior surface of the rotating drum 5. The comparatively sticky meat adheres to the surface of the drum 5 and is carried upward during drum rotation while the bones tend to slide and remain in the lower, part of the drum. The bones slide downward under gravitational force by virtue of the tilted orientation of the drum, and drop out of the lower end 7. The bones may be collected in any suitable receptacle or conveyor such as table 40 (FlG. 6) located at the lower end 7 of the drum.

As seen in FIG. 3, the meat portions of the chicken are carried upward by the drum rotation while adheringto the drum surface. A scraper element 8 is provided above a conveyor pan 9 to release the chicken parts from the drum surface causing them to drop onto the surface of the conveyor pan. The lower end of the pan 9 is supported by a bracket 10 on a frame 11 and has a guide chute 12 located beneath.

The construction of the scraper element 8 is shown in greater detail in the copending application of Lucas J. Conrad, -,Ser. No. 754,233 filed Aug. 12, 1968 Now Pat. No. 3,508,645

and assigned to the assignee of the present invention.

' The conveyor system 3 which is the subject of the present invention is mounted near the top of the drum 5 and oriented substantially parallel to the drum axis which is tilted with respect to the horizontal. The drive means in housing 6 produces a slow forward, quick reverse and rapid return motion of the conveyor pan 9 so that the sticky chicken meat is caused to advance along the surface of the conveyor pan 9 and to eventually drop from the end along the chute 12 onto a -.removal conveyor 13.

'graph of this type of motion is shown in FIG. 7. The inertia of ithese particles causes them to break free of the pan surface 'and travel forward during the large deceleration-acceleration region in the pan travel indicated by the dotted circle B. These "particles will stickto the pan during the region of travel idefined by the larger dotted ellipse A. Here the travel time of the pan from one end of its stroke to theother is substantially *the same in both directions, but there is a quick reversal at the forward end of the stroke and a slow reversal at the backward end. The type of motion required to move the parts with a low coefficient of friction with respect to the pan surface is shown .in FIG. 8. As these particles are essentially at all times sliding :"when the pan is in motion, the force from sliding friction accelerates them forward for a time f during the forward motion ,of the pan and in reverse for a time r during the return motion yr the pan cycle.,Therefore, if the time f forward is larger than Lthe time r in reverse, the effective motion of the particles is in the forward direction relative to the pan surface. Should the parts stick to the pan during the forward stroke, they still rnove generally forward since they slide during part of the return stroke. Here the travel time of the pan is faster during :reverse movement than during forward movement, but the :reversals of motion at both ends of the stroke take place Thus, in order to move all of the chicken meat particles for- :ward on the surface of the pan 9, to be dropped onto the removal conveyor 13, the motion of the pan should combine the motions shown in FIGS. 7 and 8 and execute a motion as indicated in FIG. 9. In this motion there is a quick reversal at the forward end of the stroke and a slower reversal at the backward end. Furthermore, the pan moves at a higher velocity during the return stroke and a lower velocity during the forward stroke.

The drive means of the present invention imparts a motion jt o the conveyor pan 9 in accordance with the curve shown in "FIG. 9 .While requiring a minimum of power input. This imipfroved drive means is shown in detail in FIGS. 4 and 5. The "conveyor pan 9 is mounted on the end of a drive shaft 14 .i'vhich extends through the opposite ends of the housing 6. The drive shaft 14 supports a counterweight assembly 18 within the housing 6. The assembly 18 includes two end walls 16 and $17 in which the shaft 14 is slidable. A rather stiff compression :spring 20 determines the rest position of the counterweight assembly 18 and conveyor pan 9 with respect to the brackets 21 "and 22 which support the overall assembly on the extension 4a :fixed on the support frame 4 (shown in FIG. 1). This mounting arrangement assures that under steady running conditions i:.' e., conditions other than starting up and shutting down), the reaction forces opposing the forces driving the motor are supplied by oppositely directed motions of the yieldably mounted counterweight I8 rather than by the rigid frame 4 thus reducing noise and eliminating objectionable frame. vibration.

A crossmember or set collar 15 is fastened on the drive shaft 14 and is located for reciprocal motion between the two end walls 16 and 17. The movement of the crossmember I5 between the two end walls 16 and 17 is constrained by two coil springs 23 and 24 located on either side of the crossmember lS and surrounding the shaft 14.

The shorter spring 23 is a return motion or impact spring while the longer spring 24 is a forward motion spring which cooperates with the impact spring 23 to maintain the crossmember 15 at a given position when the system is at rest. The spring rate of impact spring 23 is of the order of ten times that of the forward motion spring 24 so that when the crossmember 15 is given an impetus the particular pattern of reciprocatory motion which results is that previously described and shown in FIG. 9. The end of the spring 23 is fastened to the end wall 16 to prevent oscillation of the spring between the wall 16 and the crossmember 15 during the reciprocatory motion of the latter. The end 26 of spring 24 may be fastened to wall 17 but ordinarily it will remain under compression between the crossmember l5 and wall 17 during operation.

A fluid motor or pneumatic cylinder 27 has one of its ends attached to the crossmember 15 and operates a piston rod 28 fastened to the forward end wall 16. When pressure is applied to the right-hand end of cylinder 27, it acts against the face of a piston 27a, causing the cylinder 27 to move to the right, and the attached crossmember 15 to compress the spring 24.

A valve 29 is provided for controlling the actuation of the pneumatic cylinder 27. This valve 29, which is mounted on the base member 19, is actuated by two springloaded collars 30 and 31, encircling a rod 32. The rod 32 is attached to the crossmember l5 and is disposed substantially'parallel to the drive shaft 14 with its ends slidable inthe end walls 16 and 17. Conduit 33 supplies air to the valve 29, while conduit 34 is the exhaust line.

When the motor 27 is stopped, the parts come to rest with collar cam 31 deflecting an actuator 36 of control valve 27 so that a supply of air throughline 35 energizes power cylinder 27 compressing spring 24 between wall 17 and collar 15. This moves collar 30 into contact with'the actuator 36 of control valve 29 stopping the air supply and venting the cylinder 27. Spring 24 now accelerates the pan 9 forward via the action of shaft 14 and collar 15. Collar 31 actuates valve 29 as previously described andcollar 15 strikes impact spring 23 compressing it and decelerating the pan 9. Spring 23 now expands and assisted by air cylinder 27 accelerates the pan 9 and shaft 14 for the return stroke. After a few cycles, anequilibrium condition is reached with the power from the air cylinder 27 making up frictional losses only and the pan.9 executes continuous motion of a form shown by the displacement versus time graph of FIG. 9.

It should be understood that the disuniter 2 does not perfectly separate all the meat from the bones so that the mixture of material dropping from the lower end 7 of the drum 5 comprises some bones having meat remaining thereon. The apparatus shown in FIGS. 1-3 will act to generally sort the pieces of meat from the bones with a few pieces containing both meat and bone being mixed with both outputs. Thus the parts dropping off the end of the conveyor 9 will be mostly pieces of meat with perhaps some bones clinging thereto while the parts dropping from the lower end 7 of the drum 5 will bev mostly bones with some meat clinging thereto. The apparatus of FIG. 6 may be used to receive the parts dropping from the drumS fall on a conveyor table 40. This conveyor table 40 is driven by an improved drive means of the present invention as shown in FIGS. 4 and 5, and contained in housing 6. The con? veyor table 40 may be tilted somewhat downwardly diagonally to the right as viewed in FIG. 6, so that all the separated parts, drop from the end 42 onto the conveyor table 41 which is,

similarly driven by a drive means of the present invention.

This conveyor table 41 is tilted about its longitudinal axis so as to cause the parts deposited thereon to be drawn by gravity to the right and toward the lower side 43. As the conveyor table 41 reciprocates the bones without meat, having lower coefficients of friction, move more rapidlyalong the surface than the bones with meat, having higher coefficients of friction. During their movement then the bones advance on the surface 41 to the end edge 44 under the influence of the con veyor motion, while the bones with meat clinging to them move toward the side edge 43 of the table. In this manner the various parts may be sorted according to their frictional coefficients by placing suitable receptacles along the edges 43 and 44 of the conveyor table 41.

It will thus be seen that an improved conveyor apparatus is provided which executes suitable motion to advance particulate materials, such as disunited chicken parts in a processing line, having different coefficients of sliding friction with respect to the conveying surface. The desired motion pattern is provided by' an improved drive means' requiring a minimum power input for providing the motion and this motion may be used to sort the various parts according to their respective coefficients of friction.

We claim:

1. A conveying apparatus of the type having:

a. a member adapted to support material being conveyed;

b. means supporting said member for oscillatory movement along a path through which said material is to be'moved in a predetermined direction; and

c. means for driving said member in oscillatory movement, the improvement wherein said drivingmeans comprises:

d. first means adapted to interrupt the motion of said oscillating member in the predetermined direction and to rapidly reverse its motion; 7

e. second means adapted to restrain the motion of said oscillating member in the direction opposite the predetermined direction and to more slowly reverse its motion;

f. said first and second means interacting to produce continuous oscillatory motion of said member having a slow forward stroke, quick reversal at the end of the forward stroke, a return stroke faster than the forward stroke, and a reversal at the end of the return stroke relatively slow as compared to that at the end of the forward stroke; and

g. third means communicating an additional force to said oscillating member upon reversal of its motion by said first means, said force being of the order of the frictional losses in the apparatus.

2. Apparatus as claimed in claim 1, comprising fourth means connected to said member and wherein said first and second means comprise two springs positioned at opposite ends of the path of travel of said fourth means to produce continuous oscillatory motion of the fourth means therebetween.

3. Apparatus as claimed in claim 2 wherein the spring rate of said first means is of the order of ten times that of said second means.

4. Apparatus as claimed in claim 1 wherein said third means comprises a fluid cylinder having valve means, responsive to the relative motion between the cylinder and its piston, for introducing and exhausting the power fluid.

5. Apparatus as claimed inclaim 1 wherein the plane of the material supporting surface of said oscillating member is inclined with respect to the horizontal and said driving means is connected to said oscillating member at the upper end.

6. Apparatus as claimed in claim 1 wherein the plane of the material supportingsurface of said oscillating member is inclined about an axis in the predetermined direction such that gravity and the oscillatory motion will combine to separate the components of the conveyed material in their movement along the surface in accordance with the coefficients of friction between the respective components and the surface.

7. Apparatus as claimed in claim Zaincluding means for resiliently mounting said drive means on said supporting means comprising a counterweight supported on said fourth means and a spring acting between said counterweight and said supporting means.

8. Conveying apparatus comprising:

a. a conveyor pan adapted to support material being conveyed;

b. a shaft, connected to said pan and having a member thereon, for communicating oscillatory movement to said pan along a path through which said material is to be conveyed in a predetennined direction;

c. two springs positioned at oppositeends of the path of travel of said member to produce continuous oscillatory motion of the member therebetween;

d. motor means for driving said shaft at arelatively rapid speed through a portion of said path in a direction opposite to said predetermined direction; said motor means supplying a force to said shaft of the order of the frictional losses in the apparatus;

e. a support on which the aforesaid components are mounted, and

f. means for resiliently mounting said motor means on said support.

9. Apparatus as claimed in claim 8 wherein said motor means comprises afluidcylinder and valve means responsive to the relative motion between the cylinder and its piston for introducing and exhausting the powerfluid in said cylinder.

10. Apparatus as claimed in claim 8 wherein the surface of the conveyor pan is inclined about an axis in the predetermined direction such that gravity and the oscillatory motion will combine to separate the components of the conveyed material in their movement along the surface in accordance with the coefficients of friction between the respective components and the surface.

1]. Apparatus as claimed in claim 8 wherein said resilient motor mounting means comprises a counterweight supported on said shaft and a spring acting between said counterweight and said support. 

